Area Forecast Discussion
Issued by NWS Aberdeen, SD

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS63 KABR 251748 AAA

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1248 PM CDT Tue Jul 25 2017

Issued at 1221 PM CDT Tue Jul 25 2017

Isolated showers are currently ongoing over north central SD.
The showers, along with cloudy skies is keeping the area cooler
than expected with temps in the upper 70s and low 80s. Severe
storms are not expected in north central SD. A surface low is
currently located near KPIR with a warm front extending eastward
into western MN. Good convergence along the front, along with
daytime heating should be enough to break the cap later this
afternoon, mainly after 4 pm, CDT. Strong to severe storms are
still possible with hail and damaging winds expected. With high
PWATS, an east/west front paralleling the upper level flow, some
thunderstorms will produce heavy rainfall.


.SHORT TERM...(Today through Thursday Afternoon)
Issued at 334 AM CDT Tue Jul 25 2017

Main forecast challenge in the short term period is convective
chances later today into tonight, and the potential for severe
weather. The mid level flow will be nearly zonal today, but will see
some shortwave activity track across mainly the southern part of the
state this evening into the overnight hours. A surface warm front
associated with low pressure to the west will set up over the
southern part of the state as well, and looks to become the focus
for convection late this afternoon into tonight. The better dynamics
look to set up over southwestern Minnesota, but will see MUCAPE
values of 2500-3500 J/KG, along with bulk shear of 40 to 50 knots,
which should be enough to sustain convection, with severe storms
possible. SPC has introduced an enhanced risk over the portions of
the eastern and southern CWA, so will focus higher pops in those
locations. May see some precipitation linger into Wednesday morning,
then high pressure will drop over the area, bringing dry conditions
back to the region Wednesday afternoon through the day Thursday.

With the warm front over the area today, will see fairly warm
temperatures, with highs in the upper 80s to upper 90s. Cooler air
will move in with the surface high, with highs in the 80s Wednesday
and Thursday. Overnight lows will be in the upper 50s to mid 60s.

.LONG TERM...(Thursday Evening through Monday)
Issued at 334 AM CDT Tue Jul 25 2017

Hot mid level ridge will continue across the southern/southwestern
conus through the period. Meanwhile, a gradual increase in amplitude
of the ridge aloft is expected to occur over the Rockies/western
high plains. This will bring northwest flow back to the region, and
northwest flow is always tricky in the summer. A couple of fronts
are expected to move over the region, with some chances for rain.
However, model differences and run to run inconsistencies lend some
uncertainty to timing of pcpn and thus will have to rely on model
blend.  Temperatures overall will probably average out right around
normal for much of the forecast period.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1221 PM CDT Tue Jul 25 2017

VFR conditions are expected over the region through the valid taf
period. By late afternoon and early evening storms are expected
to light up along a front situated from KPIR/KATY. Some of those
storms will be strong to severe. Brief periods of IFR conditions
can be expected with any storms that move over a terminal.




AVIATION...SD is the U.S. government's official web portal to all federal, state and local government web resources and services.